Aerial disinfecting composition comprising polyhydroxy compound and alpha ydroxycarboxylic acid



United States Patent a as 3,160,555 AERIAL DiSl'NFEtITiWG QQRE'OEETIQN CfiiiiY-Pdfs- ENG P011. RQXY CGMPUUND AND ALPHA HYDRQXYCARBQXYLIC ACE John Hamiii and Roy Smart, Nottingham, England, assignors to Boots Pure Drug Company Limited, Nottingham, England, a British company No Drawing. Filed hiay 24, 1962, Ser. No. 197,253 Claims priority, application Great Britain, June 2, 1961, 20,087/61 8 Ciaims. ((Jl. 1673) This invention relates to improvements in bactericidal compositions. In particular it relates to novel bactericidal compositions for aerial disinfection containing as active ingredients a polyhydroxy compound and an a-hydroxycarboxylic acid.

PolyhydroXy compounds are widely used as aerial bactericides in disinfectant sprays for use in the relief of symptoms of the common cold and also in deodorant sprays. A particularly valuable member of this class of compounds is triethylene glycol. Its bactericidal eifect reaches a maximum at an aerial concentration of about 200 ng/ cu. ft. and it has been found that further increase in the concentration of triethylene glycol does not substantially increase the killing rate or the percentage reduction of the aerial organisms. This is especially so in the case of atmospheres with higher humidities.

Mixtures of polyhydroxy compounds have been prepared but these additions have not increased the activity of the compositions nor have they extended, to any eX- tent, the range of relative humidity in which the compositions are effective.

It is an object of the present invention to provide improved aerial disinfectant compositions based on polyhydroxy compounds.

We have now discovered that the addition of certain u-hydroxycarboxylic acids to an aerial disinfectant containing as active ingredient certain polyhydroxy compounds not only provides disinfectant compositions which are active over a wider range of relative humidity but surprisingly, increases the effectiveness at low and high humidity compared with that of the single components.

According to the present invention there are provided improved aerial disinfectant compositions comprising as active ingredients at least one polyhydroxy compound selected from propylene glycol, dipropylene glycol, triethylene glycol, hexylene glycol and resorcinols of the general formula:

(llH

wherein R represents hydrogen or alkyl, together with at least one u-hydroxycarboxylic acid of the general formula:

COOH

Wherein R singly represents methyl, R singly represents hydrogen, methyl or ethyl or wherein R and R together represent (CH Where n is 4 or 5.

The compositions according to the present invention may be dispersed into the atmosphere to be disinfected by various methods, for example by self-propelled pressurised aerosols, mechanical dispersal of solutions by pump or squeeze bottle, evaporation from the surface of 3,169,555 Patented Dec. 8, 1964 impregnated materials such as paper or by suitable heat vaporisation.

Self-propelled pressurised aerosol compositions according to the invention are preferably substantially anhydrous and comprise the active ingredients in association with a propellent. The preferred propellents are those low boiling fluorochloroalkanes which are available commercially under the registered trademarks Freon and Arcton. There may also be included in the basic composition liquid solvent diluents such as alcohols, ketones, ethers and halogenated hydrocarbons which may replace in part, the more expensive fluoroalkanes.

In addition to the primary ingredients, the pressurised aerosol compositions according to the invention may contain secondary ingredients compatible with the primary ingredients which may be active or inactive biologically. Biologically active ingredients include deodorants such as aliphatic aldehydes and aliphatic esters of a-methylacrylic and oc-ethylacrylic acids. Other additives may be employed to prevent corrosion of the aerosol container and these include quaternary ammonium, pyridinium and morpholinium derivatives. Aromatic compounds such as menthol, camphor, oil of eucalyptus and oil of wintergreen or sympathomimetic amines may be included to aid in relief of symptoms of the common cold. Perfumes may be added if so desired.

The compositions of the invention adapted for mechanical dispersion into the atmosphere comprise the active components in association with a solvent diluent, for example water or the lower alkanols. For economic reasons, water is the preferred diluent. Compatible additives such as deodorants, aromatic compounds, sympathomimetic amines and perfumes may also be included if desired.

Materials such as paper may be impregnated by saturation with an ethereal or other suitable solution of the active ingredients.

The activity of the compositions according to the present invention has been assayed by the method described in British Standard No. 2796, Preliminary Assessment of Aerial Bactericides, using as test organism Staphylococcus albzls NCTC 7944. Aerosol packs were formulated so that a 5 second burst produced a required concentration of bactericide in a room of 1200 cu. ft. capacity. Samples were taken from the test room at intervals and the killing rate K was derived from the formula:

where in and n are the numbers of viable organisms counted in air samples taken with a time interval of t minutes between samples.

The minimum satisfactory reduction in bacterial count laid down in British Standard 2796 is of the test organisms in 4-6 minutes and is equivalent to a killing rate of approx mately 22. Tests were carried out on aerosol formulations containing 3% of triethylene glycol only at relative humidities of less than 55% and a further series of tests were carried out at humidities of greater than 55%.

At the optimum concentration of -200 pug/C11. ft., the killing rate at the low humidi-ties was of the order of 20 to 25 but at the higher humidity the killing rate was much lower. A similar dependence on relative humidity was found with other polyhydroxy compounds, the resorcinols being more eftective at higher humidities.

Additions of a-hydroxycarboxylic acids were made to the polyhydroxy compound formulations and a surprising improvement was shown in the bactericidal activity. Particularly active compositions were prepared using ahydroXy-ct-methylbutyric acid and a preferred composition contained 3% of triethylene glycol and 2.4% of a-hydroxy-a-methylbutyn'c acid. A 5 second burst from such a composition in a room of 1200 cu. ft. capacity is equivalent to an aerial concentration of 125-150 g/cu. ft. of triethylene glycol and 100-120 ,ug./C l1. ft. of the hydroxy acid, these concentrations being estimated from the weight of composition discharged from the container. In the following tables, the mean killing rates of aerosols containing polyhydroxy compounds and cc-l'iYdI'OXY- carboxylic acids are compared with the killing rates for the separate ingredients. The figure in brackets after the killing rate is the number of tests comprising the mean killing rate.

TABLE I.-FORMULATIONS OF TRIETHYLENE GLYCOL AND a-HYDROXY-a-METHYLBUTYRIC ACID (C- Relative Humidity Relative Humidity less than 55% 60%i5% C =acid, -I011. ft.

'IEG, ug/cu. it. TEG, gJcu. ft.

TABLE II.FORMULATIONS OF 'IRIETHYLENE GLYCOL TABLE Iii-FORMULATIONS OF HEXYLRESOROINOL (H.

RES) AND C-ACID Relative Humidity Relative Humidity less than 55% 60%i5% H. Res, gJcu. ft. 11. Res, gJcu. ft.

TABLE IV.FORMULATIOILJSIDOF RESORCINOL AND C- Relative Humidity Relative Humidity less than 55% 6G% 5% G=acid, gJcu. It.

Resorcinol, gjcu. it. Resorcinol, ,ugjcu. it.

The tables show that compositions containing both onhydroxycarboxylic acids and the polyhydroxy compounds hereinbefore defined are highly bactericidal at low and high humidities.

When tested in a similar way mixtures of a-hydroxycarboxylic acids or mixtures of the polyhydroxy compounds hereinbefore defined did not show higher killing rates at low or high humidity compared with the single ingredients and no mixture showed worth while activity at both ranges of humidity.

In addition to the standard tests using Staphylococcus albus as the test organism, the compositions of the present invention have been tested in the standard test room against the following organisms with excellent killing rates in each case at low and high humidity.

Streptococcus salivarius (in saliva) Streptococcus salivarius (in peptone water) Pseudomonas Proteus vulgaris Escherichia coli Serratia marcescens Influenza A virus Bacteriophage Pc of Pseztdomonas pyocyanea For example, the composition described in Example 1, Composition A, was compared with two commercially available aerial disinfectants B and C using influenze A virus in the test chamber.

Aerial disinfectant B contained 1.5 resorcinol and 0 10-20 0 10-20 v 2.25% propylene glycol.

Aerial disinfectant C contained 3% triethylene glycol 20.0 (2) 57 (1) 100-130 13.6 (9) 53.8 (2) 20 9 (13) 69 (1) and 3% dipropylene glycol.

The inactivation rates are shown graphically below.

INACTIVATION OF INFLUENZA A VIRUS AT 50% RELATIVE HUMIDITY 515 CONTROLS an it 0.1 w-t F-l U] 1 l w l l v I r i l 5 10 Time in minutes It is evident that virus inactivation with the composition A of the present invention is approximately times as effective as that using conventional aerial disinfectants.

In addition aenial disinfectant B was compared with composition A using Streptococcus salivarius in saliva as the test organism. Table V shows the superiority of composition A over the commercially available aerial disinfectant.

TABLE V.COMPARISON OF AERIAL DISINFECTANTS AGAINST STREPTOCOCC' US SALIVARIUS IN SALIVA Example 2 A cold relief aerosol was prepared from the following ingredients:

Percent Triethylene glycol 3 a-Hydroxy-a-methylbutyric acid 2.4 Menthol 1 Camphor 0.4 Oil of eucalyptus 0.5 Isopropyl alcohol 10 Arcton 114-Arcton 12, 50/50 mixture to 100%. Vapour pressure to 50 lb./sq. in. at normal room temperature.

Example 3 An aerosol composition was prepared from the following ingredients:

Percent Triethylene glycol 3 a-Hydroxy-a-methylbutyric acid 1.2 Isopropyl alcohol 10 Arcton 11-Arcton 12, 50/50 mixture to 100%. Vapour pressure, 45 1b./sq. in. at normal room temperature.

Example 4 An aerial disinfectant composition for dispersal by mechanical means was prepared from the following ingredients:

Percent u-Hydroxy-u-methylbutyric acid 9.6 Triethylcne glycol 12.0 Water to 100%.

6 Example 5 A self-propelling aerial disinfectant composition was prepared containing:

Percent Resorcinol 1.5 cL-HYdI'OXY-a-HifiihYlbllllYliC acid 1.2 Isopropyl alcohol 12.7 Arcton l1 propellent 37 Arcton 12 propellent 47.6

This composition when sprayed to give a concentration of approximately 5060 ,ag./cu. ft. of C-acid gave a percentage reduction of test organisms exceeding 99% at both low and high humidity.

Example 6 A self-propelling aerial disinfectant was prepared with the following composition:

Percent rx-HYdIOXY-u-mCthYlbHtYl'iC acid 2.4 Hexylresorcinol 0.3 Isopropyl alcohol 12.7 Arcton 11 propellent 37 Arcton 12 propellent 47 .6

When sprayed to give a concentration of C-acid of 100- agi/cu. ft. there was obtained a 99% reduction in test organisms at low and high relative humidity.

Example 7 Aerial disinfectant compositions were prepared in a similar way to that described in Example 1 but replacing the triethylene glycol by 3% of one of the following glycols:

Propylene glycol Dipropylene glycol Hexylene glycol Example 8 Aerial disinfectant compositions were prepared in a similar way to that described in Example 1 but replacing the a-hydroxy-a-methylbutyric acid with 2.4% of:

a-Hydroxyisobutyric acid Cyclo'nexanol-l-carboxylic acid We claim:

1. Aerial disinfectant compositions comprising as active ingredients at least one polyhydroxy compound selected from the group consisting of propylene glycol, dipropylene glycol, triethylene glycol, hexylene glycol and resorcinols of the formula:

wherein R is selected from the group consisting of hydrogen and lower alkyl together with a-hydroxy-a-methylbutyric acid.

2. Aerial disinfectant compositions as in claim 1 which are self-propelled and substantially anhydrous comprising the active ingredients as defined in claim 1 in association with a liquid mixture of propellent fiuorochloroalkanes.

3. Aerial disinfectant compositions as in claim 1 which are self-propelled and substantially anhydrous comprising the active ingredients as defined in claim 1 in association with a liquid mixture of propellent fiuorochloroalkanes and an inert solvent in addition to said fluorochloroalkanes.

4. Aerial disinfectant compositions as in claim 1 comprising the active ingredients as defined in claim 1 in association with an inert solvent diluent.

5. Aerial disinfectant compositions as in claim 1 com- References Cited in the file of this patent prising the active ingredients as defined in claim 1 in UNITED STATES PATENTS association with water as an inert solvent diluent.

6. Aerial disinfectant compositions as in claim 1 com 1772975 Wleland 1930 prising the active ingredients as defined in claim 1 in 5 2,333,124 Robertsqn et July 23, 1941 association With ether as an inert solvent dilnent. 2,546,895 Jarowskl 1951 7. An aerial disinfectant composition consisting essen- FOREIGN PATENTS tially of 3% triethylene glycol, 2.4% a-hydroxy-rx-methylbutyric acid, 10% isopropyl alcohol and 84.6% of a mix- 8: 25 fig g ture of propellent fiuorochloroalkanes. 10 n 8. A method of aerial disinfection wherein the air space 7 OTHER REFERENCES to be disinfected is exposed to a composition as claimed Wyss et al.: Archives of Biochemistry, vol. 7, Julyin claim 1. September 1945, pp. 415-425. 

1. AERIAL DISINFECTANT COMPOSITIONS COMPRISING AS ACTIVE INGREDIENTS AT LEAST ONE POLYHYDROXY COMPOUND SELECTED FROM THE GROUP CONSISTING OF PROPYLENE GLYCOL, DIPROPYLENE GLYCOL, TRIETHYLENE GLYCOL, HEXYLENE GLYCOL AND RESORCINOLS OF THE FORMULA: 